Pitman for mowing-machines



(No Model.) 7

DEWITT G. MARKHAM.

PITMAN FOR MOWING MACHINES.

Patented Feb. 10, 1885.

:I Is I 5::

WITNESSES ATTORNEY.

llama S'ra'rns ATENT FFICEQ PITMAN FOR MOWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 311,996, dated February 10,1885.

(No model.)

T all whom it may concern:

Be it known that I, DEWITT O. MARKHAM, a citizen of the United States, residing at T0- wanda, in the county of Bradford and State of Pennsylvania, have invented certain new and useful Improvements in Pitman-Oonnections for MowingMachines; and I do hereby declare the following to be a full, clear, and exone in which the knife is actuated by an os-.

cillating rock-shaft, motion being conveyed to the rock-shaft from some rotating part of the machine by means of a pitman-rod. A machine of the character here indicated is described in Letters Patent No. 304,837, granted to me September 9, 1884.

The present invention has for its object to so connect the pitman-rod to the rock-shaft and to some rotating part of the machine that a tight joint between said parts can always be maintained, provision being made whereby the wear between the parts may be taken up readily and without removing any of the parts, and at the same time the connections are so made as to allow for the slight lateral motion of the pitman-rod.

In order that the construction of the parts whereby the objects of my invention are secured may be clearly understood, I will describe it in connection with the accompanying drawings, in which- Figure l is a top view of a part of a mowing-machine, only so much being shown as will enable the operation of the pitman to be understood. Fig. 2 is a side view of the upper part of the pitman-rod, showing the connections with the operating parts of the mowing-machine. Fig. .8 is a central vertical longitudinal section of the parts shown in Fig. 2, and Fig. 4 is a similar section of the connections between the pitlnan and the rockshaft.

Like letters designate corresponding parts in all of the figures.

, the pitman.

Rotated by suitable connecting mechanism with some moving part of the mowing-machine is a wheel, A, on the face of which .is eccentrically placed. a wrist-pin, a. This pin is connected to a pitmanrod, B, which at its lower end is connected to a rock-shaft, O, which conveys reciprocating motion to the knife D. The wrist-pin a and the rock-shaft O areeach formed with a spherical head, 12, on the end which connects with the pitman. The connections of both the wrist pin and rockshaft with the pitman are in the main identical, so that a description of one will suffice for both. The spherical head 1) plays in a box which is divided into two similar parts, EE. These parts are constructed so as to provide a socket to fit over the head I). The parts E E are also hollowed out on the side through which the wrist-pin or rock-shaft passes, as shown at c, to allow for the slight lateral movement of the pitman. The box E E is held in a strap, F, which is secured to the pitman B.

In order to hold the boxes securely in place in the straps, and at the same time take up the wearon the boxes, the connections between the pitman and straps are different at the two ends of the pitman. At one end, (1, (see Fig. 4,) the pitman is screw-threaded, and screws directly through the strap F against the box E E, it being screwedtightly enough to hold the box securely in place. As the box wears loose the pitman can be screwed up farther, and so take up the wear, thus securing the steady and easy working of At the other end of the pitman the end 6 (see Fig. 3) is also screw-threaded; but it does not screw directly into the strap F. It screws into a plug, G, which screws into the strap F against the box E E, holding it in position. As the box at this end wears loose the plug G can be screwed up independently of the pitman, which, however, enters so far into the plug that it is always securely held therein.

I claim as my invention 1. A box forming a bearing, and a strap inclosing said box, in combination. with a plug externally and internally screw-threaded, which screws through said strap against said box, and a pitman-rod which screws into said plug. I

2. Two bearing-boxes and two straps in In testimony whereoflaffix my signature in ro closing the same, in combination with avplug presence of two Witnesses. externally and internally screw-threaded, which screws into one of said straps and DEWITT G. MARKHAM. against its inclosed bearing-box, and a pitman-rod which screws into said plug at one Witnesses:

end and at the other end into the other strap M. W. Ross, and against the inclosed bearingbox, snbstan- J NO. E. FOX. tially as and for the purpose set forth. 

